摘要： 刚装完CentOs但不能上网，很是纠结。service network restart出现下面错误：Error: Connection activation failed: Device not managed by NetworkManager原因：系统中有两个服务在管理网络，所以需要停掉一个解决方案：1、Remove Network Manager from startup Service#chkconfig NetworkManager off2. Add Default NetManager#chkconfig network on3.Stop NetworkManager first 阅读全文